General. To study the roles of polar lipids of the nervous system of man and animals and define changes in neuropathology by accurate, precise, quantitative determination of the types and amounts of lipid classes (including trace components) and their fatty acid compositions in whole brain and subcellular particulates and to correlate findings with data on anatomy, physiology, enzymology, permeability etc. Specific. 1) To define more completely the age-related changes in the lipid composition of normal human and animal brains; 2) To define lipid class interrelationships precisely by graphic and computer analysis; 3) To define alterations in pathological states with emphasis upon neuropathology and hereditary metabolic diseases; 4) To define alterations in mouse neurological mutants in an effort to obtain models of human disease with animals for which extensive genetic data are available; 5) To formulate in detail the structures of cellular membranes of the nervous system from lipid, protein, and other data and correlate structure with function; 6) To train investigators from other laboratories in the use of new and improved methods, and to standardize methodology.